Bone marrow stromal cells inhibits HMGB1-mediated inflammation after stroke in type 2 diabetic rats

High-mobility group box 1 (HMGB1), a ligand of receptor for advanced glycation endproducts (RAGE), functions as a proinflammatory factor. It is mainly involved in inflammatory activation and contributes to the initiation and progression of stroke. By using a model of transient middle cerebral artery occlusion (MCAo) in type 2 diabetic rats, we investigated the changes of pro-inflammation mediators, blood-brain barrier (BBB) leakage and functional outcome after stroke. Type 2 diabetic rats did not show an increased lesion volume, but exhibited significantly increased expression of HMGB1 and RAGE, BBB leakage, as well as decreased functional outcome after stroke compared with control rats. Injection of bone marrow stromal cells (BMSCs) into type 2 diabetic rats significantly reduced the expression of HMGB1 and RAGE, attenuated BBB leakage, and improved functional outcome after stroke. BMSCs-treated type 2 diabetic rats inhibited inflammation and improved functional outcome after stroke. Furthermore, in vitro data support the hypothesis that BMSCs-induced reduction of HMGB1 and RAGE in T2DM-MCAo rats contributed to attenuated inflammatory response in the ischemic brain, which may lead to the beneficial effects of BMSCs treatment. Further investigation of BMSCs treatment in type 2 diabetic stroke is warranted.

Immune influence of pregnancy on human H7N9 infection: a case report

INTRODUCTION

H7N9 infection has raised serious concerns worldwide. Pregnant women were considered to be at a high risk of influenza infection. Normal pregnancy was dependent on T helper (Th) 2 deviation. However, whether pregnancy influences the immune status of influenza H7N9 patients has not been reported.

CASE REPORT

Here, we reported a case of pregnant woman in the first trimester with H7N9 infection compared with the two non-pregnant female H7N9 patients for clinical features and relevant immunological changes. We found that there were no differences in plasma levels of Th1 and Th2 cytokines between the pregnant and non-pregnant patients, and there was no Th2 deviation in the acute phase. However, the Th2 deviation was recurrent along with the clearance of infection in the H7N9 pregnant patient.

CONCLUSION

These cases highlighted that the pregnant patient infected with H7N9 could induce an effective Th1 immune response equal to that of non-pregnant patients with H7N9 virus infection, although the pregnancy itself could lead to a Th2 deviation. These data suggested that pregnant patients could acquire a similar antiviral response for H7N9 infection versus non-pregnant patients.

CtBP maintains cancer cell growth and metabolic homeostasis via regulating SIRT4

Cancer cells rely on glycolysis to maintain high levels of anabolism. However, the metabolism of glucose via glycolysis in cancer cells is frequently incomplete and results in the accumulation of acidic metabolites such as pyruvate and lactate. Thus, the cells have to develop strategies to alleviate the intracellular acidification and maintain the pH stability. We report here that glutamine consumption by cancer cells has an important role in releasing the acidification pressure associated with cancer cell growth. We found that the ammonia produced during glutaminolysis, a dominant glutamine metabolism pathway, is critical to resist the cytoplasmic acidification brought by the incomplete glycolysis. In addition, C-terminal-binding protein (CtBP) was found to have an essential role in promoting glutaminolysis by directly repressing the expression of SIRT4, a repressor of glutaminolysis by enzymatically modifying glutamate dehydrogenase in mitochondria, in cancer cells. The loss of CtBP in cancer cells resulted in the increased apoptosis due to intracellular acidification and the ablation of cancer cell metabolic homeostasis represented by decreased glutamine consumption, oxidative phosphorylation and ATP synthesis. Importantly, the immunohistochemistry staining showed that there was excessive expression of CtBP in tumor samples from breast cancer patients compared with surrounding non-tumor tissues, whereas SIRT4 expression in tumor tissues was abolished compared with the non-tumor tissues, suggesting CtBP-repressed SIRT4 expression contributes to the tumor growth. Therefore, our data suggest that the synergistically metabolism of glucose and glutamine in cancer cells contributes to both pH homeostasis and cell growth. At last, application of CtBP inhibitor induced the acidification and apoptosis of breast cancer cells and inhibited glutaminolysis in engrafted tumors, suggesting that CtBP can be potential therapeutic target of cancer treatment.

An assessment of wetland nature reserves and the protection of China’s vertebrate diversity

We assessed all 148 wetland nature reserves in China and the distribution of the four taxa of endemic and threatened terrestrial vertebrates, reptiles, amphibians, birds and mammals. Assessment of the wetland nature reserves was combined with the governmental list of the endemic and threatened vertebrates to identify the richness of the species. Species richness was scored as high, medium or low using a factor analysis method, and 31 wetland ecosystems were marked as high protection areas. The relationship between the threatened species and the endemic species in the reserves was also analyzed. We found that both richness patterns were similar. Based on the richness study, a nature reserve classification system with corresponding.

COUP-TFII regulates metastasis of colorectal adenocarcinoma cells by modulating Snail1

BACKGROUND

Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII, also known as NR2F2) promotes metastasis by functioning in the tumour microenvironment; however, the role of COUP-TFII in colorectal cancer remains unknown.

METHODS

Human colon adenocarcinoma tissues were collected to test COUP-TFII expression. Wound-healing and cell invasion assay were used to evaluate migration and invasion of cells. Chicken ovalbumin upstream promoter-transcription factor II and related protein expression was assessed by immunostaining, immunoblotting and real-time PCR assay. Tamoxifen-inducible COUP-TFII knockout mice were employed to test COUP-TFII functions on colon cancer metastasis in vivo.

RESULTS

Elevated expression of COUP-TFII in colorectal adenocarcinoma tissue correlated with overexpression of the Snail1 transcription factor. High COUP-TFII expression correlated with metastasis and shorter patient survival. Chicken ovalbumin upstream promoter-transcription factor II regulated the migration and invasion of cancer cells. With Snail1, COUP-TFII inhibited expression of adherence molecules such as ZO-1, E-cadherin and β-catenin in colorectal cancer cells. Overexpression of COUP-TFII was required for cancer cells to metastasise in vivo. Chicken ovalbumin upstream promoter-transcription factor II regulated the transcription and expression of Snail1 by directly targeting the Snail1 promoter and regulated associated genes.

CONCLUSIONS

Chicken ovalbumin upstream promoter-transcription factor II was crucial for colorectal cancer metastasis and regulated cell migration and metastasis in conjunction with Snail1. Chicken ovalbumin upstream promoter-transcription factor II was found to be a biomarker associated with patient survival and colorectal cancer metastasis.

Cardiovascular toxicity of different sizes amorphous silica nanoparticles in rats after intratracheal instillation

The purpose of this work was to investigate the cardiovascular toxicity of different sizes and different dosages of silica nanoparticles in Wistar rats. The three silica nanoparticles (30, 60, and 90 nm) and one fine silica particles (600 nm) at three doses of 2, 5, and 10 (mg/Kg bw) were used in the present experiment. After intratracheal instillation for a total of 16 times, concentration of Si in hearts and serum was measured by inductively coupled plasma optical emission spectrometer. The hematology parameters were analyzed by an automated hematology analyzer, and the inflammatory reaction, oxidative stress, endothelial dysfunction, and the myocardial enzymes in serum were measured by kits. Our results showed intratracheal-instilled silica nanoparticles could pass through the alveolar-capillary barrier into systemic circulation. Concentration of Si in the heart and serum depended on the particles size and dosage. The levels of reactive oxygen species (ROS) at 5, 10 mg/Kg bw of the three silica nanoparticles were higher than the fine silica particles. Blood levels of inflammation-related high-sensitivity C-reactive protein and cytokines such as interleukin-1beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha were increased after exposure to three silica nanoparticles at 10 mg/Kg bw. Moreover, the levels of IL-1β and IL-6 at 10 mg/Kg bw of silica nanoparticles (30 nm) were higher than the fine silica particles. Significant decrease in superoxide dismutase, glutathione peroxidase and significant increase in malondialdehyde were observed at 10 mg/Kg bw of the three silica nanoparticles. A significant decrease in nitric oxide (NO) production was induced which coincided with the reduction of nitric oxide synthase (NOS) activity and the excessive generation of ROS in rats. The levels of intercellular adhesion molecule-l and vascular cell adhesion molecule-l elevated significantly after exposure to three silica nanoparticles at 10 mg/Kg bw, which are considered as early steps of endothelial dysfunction. We conclude that cardiovascular toxicity of silica nanoparticles could be related to the particles size and dosage. Oxidative stress could be involved in inflammatory reaction and endothelial dysfunction, all of which could aggravate cardiovascular toxicology. In addition, endothelial NO/NOS system disorder caused by nanoparticles could be one of the mechanisms for endothelial dysfunction.

Expression of interleukin-22 in myasthenia gravis

IL-17 and IL-22 are implicated in the pathogenesis of autoimmune diseases. The roles of IL-22 in the pathophysiology of myasthenia gravis (MG) remain unsettled. The aim of this study was to investigate the possible relationship between serum IL-22, IL-17 levels, anti-acetylcholine receptor antibody (anti-AChR Ab) titres and clinical parameters in patients with MG. The serum IL-22, IL-17 levels and anti-AChR Ab titres were tested by enzyme-linked immunosorbent assay (ELISA), while the expression of IL-22 and IL-17 mRNAs in peripheral blood mononuclear cells (PBMC) from healthy and MG subjects were detected by quantitative real-time PCR (qRT-PCR). Furthermore, PBMC from 12 patients with generalized MG were purified and treated with recombinant human IL-22 (rhIL-22), the IL-17 levels of supernatant were detected by ELISA. We found that the IL-17 levels were significantly increased, but IL-22 levels were significantly decreased in the serum of patients with MG compared with healthy controls. Consistantly, a significant decrease in IL-22 mRNA levels and an increase in IL-17 mRNA levels were detected in PBMC collected from patients with MG, compared with healthy controls. A negative correlation between IL-22 mRNA in PBMC, serum IL-22 and serum anti-AChR Ab levels was found in patients with MG. Moreover, in cultured MG PBMC treated with recombinant human IL-22 (rhIL-22), the IL-17 levels were decreased in a dose-dependent manner. Our findings indicated a possible role of IL-22 as a protective factor in MG.

Growth, Characterization, and Application of High Al-content AlGaN and High Power III-Nitride Ultraviolet Emitters

A study of Si-doped and Mg-doped AlxGa1-xN up to × ∼ 50 % and the characteristics of ultraviolet (UV) light emitting diodes (LEDs) with emission wavelengths at 340 nm and 290 nm are reported. By using grading super-lattices (SLs) before n-type AlGaN growth, surface roughness is much improved. Resistivity of 2.9×10-2 Ωcm and free electron concentrations of 2.9×10 cm- are achieved for n-type Al0.45Ga0.55N. The viability of effective p-type doping is defined by a minimum concentration of Mg required to offset the background impurities and, more importantly, a maximum limit above which inversion domains and structural defects start to nucleate, accompanied by a rapid degradation of electrical transport. Resistivity of 10 Ωcm and free hole concentrations above 1017 cm−3 are achieved for AlxGa1-xN up to × ∼ 50 % within an optimum window of Mg incorporation. Output powers up to 1.5 mW from small area 340 nm LEDs (< 100 μm diameter) and 110 μW from 290 nm LEDs (100 μm diameter) directly off a planar chip have been achieved under DC condition. For large area encapsulated lamp (1×1 mm2 device area and 0.52 mm2 mesa area), output power of 79 mW from 340 nm LEDs and 8.5 mW from 290 nm LEDs are achieved under pulse mode (1kHz, 2% duty factor).